commit 4912d6990b806177733efc1365110cd2d92513fa
author Zhao Liu <zhao1.liu@intel.com> Tue Jul 30 12:55:42 2024 +0800
committer Paolo Bonzini <pbonzini@redhat.com> Wed Jul 31 13:13:31 2024 +0200
tree e559f29b5649358d7ce30cea4bec62a3338ed91c
parent eee194dd7120f62896d5fbffeba8ab2ec39a09da

target/i386/cpu: Explicitly express SGX_LC and SGX feature words dependency

At present, cpu_x86_cpuid() silently masks off SGX_LC if SGX is absent.

This is not proper because the user is not told about the dependency
between the two.

So explicitly define the dependency between SGX_LC and SGX feature
words, so that user could get a warning when SGX_LC is enabled but
SGX is absent.

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20240730045544.2516284-3-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

target/i386/cpu.c

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index a953528..e864f55 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -1730,6 +1730,10 @@
         .from = { FEAT_7_1_EAX,             CPUID_7_1_EAX_WRMSRNS },
         .to = { FEAT_7_1_EAX,               CPUID_7_1_EAX_FRED },
     },
+    {
+        .from = { FEAT_7_0_EBX,             CPUID_7_0_EBX_SGX },
+        .to = { FEAT_7_0_ECX,               CPUID_7_0_ECX_SGX_LC },
+    },
 };
 
 typedef struct X86RegisterInfo32 {
@@ -6545,11 +6549,6 @@
                 *ecx |= CPUID_7_0_ECX_OSPKE;
             }
             *edx = env->features[FEAT_7_0_EDX]; /* Feature flags */
-
-            if ((*ecx & CPUID_7_0_ECX_SGX_LC)
-                    && (!(*ebx & CPUID_7_0_EBX_SGX))) {
-                *ecx &= ~CPUID_7_0_ECX_SGX_LC;
-            }
         } else if (count == 1) {
             *eax = env->features[FEAT_7_1_EAX];
             *edx = env->features[FEAT_7_1_EDX];